SQL-连接同一表中的行

SQL-连接同一表中的行

创建测试数据：

SQL> create table ecom_page_meta (post_id number not null  2      , meta_name varchar2(15) not null  3      , meta_value varchar2(15) not null);Table created.SQL> insert into ecom_page_meta values (1, 'bar', '44');1 row created.SQL> insert into ecom_page_meta values (1, 'foo', 'on');1 row created.SQL> insert into ecom_page_meta values (2, 'bar', '1');1 row created.SQL> insert into ecom_page_meta values (2, 'foo', 'on');1 row created.SQL> insert into ecom_page_meta values (3, 'bar', '1');1 row created.SQL> insert into ecom_page_meta values (3, 'foo', 'off');1 row created.SQL> commit;Commit complete.

查询以给出与OP样本匹配的结果：

SQL> select L.post_id, L.meta_name, R.meta_name, L.meta_value, R.meta_value  2  from ecom_page_meta L  3  inner join ecom_page_meta R  4      on L.post_id = R.post_id  5      and L.meta_value <> 'on'  6      and R.meta_value = 'on'  7  where L.meta_name = 'bar';   POST_ID meta_NAME       meta_NAME       meta_VALUE      meta_VALUE---------- --------------- --------------- --------------- ---------------         1 bar  foo  44   on         2 bar  foo  1    on

我仍然不知道该

WHERe t1.meta_name = 'featured-products'

怎么做，因为没有示例数据包含字符串“ featured-products”的t1.meta_name。